Art of manufacturing coffee



`Fune 29, 1937. L. s. MAEDE 2,085,376

ART 0F MANUFACTURING COFFEE Filed Aug. 28, 1953 4 Sheets-Sheet l s l l ll l l l 1 BY ATTO NEYS 4 Sheets-Sheet 2 June 29, 1937. L. s. MAEDE ARTOF MANUFACTURING COFFEE Filed Aug. 2s, 1953 June 29, 1937.

L. s. MAEDE ART 0F MANUFACTURING COFFEE Filed Aug. 28, 1933 4Sheets-Sheet 3 ATTORNEYS June 29, 1937. L. s. MAEDE 2,085,376

ART 0F MANUFACTURING COFFEE Filed Aug. 28, 1933 4 Sheets-Sheet 4 MMMATTORNEYS greeted June ze, i937 2,085,376

f AC'EURING COFFEE Leland S. Mia/ede, Brooklyn, N. Y. Application August28, 1933, Serial No. 687,078 3 Claims. (Cl. iig- 65) This inventionrelates to a coffee having a bet- Another object is to disclose andprovide a ter avor and a more readily eXtr-actable flavor method ofrapidly and economically grinding and long continued vibration in thecontainers so that description. In order to facilitate understandlo thepurchaser is assured of a homogeneous deing of the invention, referencewill be had to the sired blend. appended drawings, in which Furthermore,the coiee of this invention is Fig. l diagrammatically illustrates thearsired size and distribution which appears to imand the movement of thecoffee beans, chaff, etc., l5

tion or drip purposes. Furthermore the product paratus. of thisinvention is the result of a single grind- Fig. 3 is a plan VieW 0f themOtOr drive Which ing operation and the mixing or blending is carforms apart of the grinding apparatus. 20 ried out in such manner that theparticles of the Fig. 4 is an enlarged vertical longitudinal secproductare relatively sharp and clean and do not tion through a pOltiOn 0f thegrinding apparatus contain as large quantities of dust nor theroundillustrated in Fig. 2.

ed worn particles of ordinary coffee. Fig. 5 is a horizontal sectionthrough one of the The present invention also relates to a methodgrinding units.' 25 of grinding and treating coffee whereby the prod-Fig. 6 is a vertical longitudinal section taken uct above identined isobtained. Ordinarily, along the plane VI-VI of 'g. 5, showing the coffeeis subjected to a plurality of grinding opguiding frame and bearingblock assembly.

.Fig 7 is aivertical transverse section taken to considerable aeration.Whenever coffee isalong the piane VII-VII 0f Fig. 6. 3U

g. 8 is a vertical section taken along the its volatile ilavoringingredients or constituents. plane VIII-VIIID Fig. 4. ShOWing the methodThe present method contemplates but a single 0f suspending the shakerassembly from the body grinding and very little aeration. Furthermore,frame 0f the grinding apparatus. the beans are ground in the absence ofchaff, the As ShDWn in Fig. 1, the roasted coffee beans 35 o chaff 1salso Separately ground The chaff and supply and distribution of coffeeto the cracking 40 For the purpose of placing the method into 0pperportion of the Screen. The finely divided eration, it has been foundthat a particular ar- Cracked COee passes through the screen 8 Ontorangement of elements gives the preferred reaehute 9- The largerparticles 0f Coffee, together 0 suits, with the chair, move along thescreen 8, the larg- 50 One of the objects of this inventionv is to diserparticles eventually falling OnO a grille Work close a nely dividedcoffee adapted for percolatermed a string Catcher l0- At the point tion,boiling or drip, such coiee being characwhere the chair and largeparticles would fall 01T terized by its relative freedom fromstratification the end of the shaker screen 8, suction is nnhuml andenhanced :davor extraction properties. tbrmm* dened particle size movesor separates the chaff from the larger particles. The separation ofchaff and coffee is substantially complete at this point because it isbeing made in the absence of iinely divided coiee. It is to be notedthat any iinely divided coffee produced by the cracking rolls t and 1would have passed through the screen' 8 before reaching the point` atwhich the suction is applied.

The chaii is conveyed, as indicated by the arrows, through a suction fanl2 and into a chai collector i3 from whence it is discharged into a changrinder lli. Chai-f grinders are known in the art and generally operateby rapidly throwing and brushing the chai against surface or screen.

The grille or string catcher |13' retains large impurities such asstrings, etc., and directs them away from the grinding rolls. Coffeefree from chaff and from coarse impurities is thus directed into thegrinding rolls which comprise a slow speed circumferentially ribbed roller oppositely driven, longitudinally ribbed roll i6. The finishing orgrinding rolls l5 and i6 comminute the coffee to the required state ofdivision. The ground coffee then passes into the hopper of a mixer ornormalizer l1 wherein it is intimately but gently mixed with groundchaff from the chaii grinder I4. The mixer l1 is provided with spiralflight agitators driven by means not shown. It is similar inconstruction to mixing machines used in this art but is preferably ofmuch larger capacity and is driven at a much lower speed so as not tosubject the coiiee to a violent rubbing or attrition. The coiee thustreated is then sent to the packing machines.

In the above description, the coiiee has been traced through one-half oithe complete grinding unit. The other half is similarly constructed andlike elements or parts have been marked with like numerals.

The grinding operation described hereinabove is carried out in suchmanner as to produce a coiee having the following screen analysis:

, Percent Remaining on a No. 5 sieve 0.5-1.2 Remaining on a No. 41/2sieve 6.5-8.0 Remaining on a No. 4 sieve 2'1-29 Remaining on a No. 28sieve 50-54 Passing through a B screen as dust 10-13 Although the abovescreen analysis is representative of the preferred particle sizeclassication, the following is a more detailed and more specific rangeof preferred sizes:

- Per cent Remaining on a No. 5 sieve 0.65-1.0 vRemaining on a No. 41/2sieve 'LO-1.25 Remaining on a No. 4 sieve 2'1.5-28.5 Remaining on a No.28 sieve 52.5-53.0 Passing through a B screen as dust 10.512.0

Attention is called in this connection to the fact that the preferredcoffee preferably contains no appreciable quantity of material on a No.51/2 sieve and onlyA a very small quantity, less than 1.2%, remains on aNo. 5. The major proportion ofthe coffee, that is, over '10% thereof,will pass a No. 41/2 but will be retained on a No. 28. This isparticularly notable in View of the fact that all of the chaff ispresent in the coffee. It has been found that a coffee having the aboveclassication when made in accordance with the method describedhereinabove will not stratify upon shipment and has a foraminousmaterially enhanced avor extraction properties.

The grinding apparatus dlagramrnatically illustrated in Fig. l is shownin more detail in the other drawings. The general arrangement of hopper,cracking rolls and grinding rolls is identical to that shown in Fig. l.apparatus is preferably built in duplicate so as to contain two sets ofcracking and grinding rolls, although coffee is passed through thegrinding rolls but once.

As' shown in Figs. 2 and 3, the grinding apparatus includes a body frame2Q on which are mounted the duplicate cracking and grinding rolls. Oneof the distinguishing characteristics of this apparatus is the mountingoi the rolls so that they are easily adjustable and at the same timeheld with s mcient rigidity so as to prevent separation oi opposingrolls. Both cracking and grinding rolls may. be mounted in bearingblocks adjustably positioned within guiding frames 2| which in turn arealso adjustably positioned on the body frame 2B. Detailed constructionof the guiding frames and appurtenances is shown in Figs. 6 and 7.

As there shown, the guiding frame 2| is preferably of rectangular form,including top, bottom and end plates fastened together in a suitablemanner as by means of machine screws. guiding frame 2| is adjustablyconnected to the body frame 20 as by means of bolts 22, said boltsextending through slots 23 formed in the horizontal portion of -the mainframe 20. Movably positioned within the guiding frame 2| are bearingblocks 26 and 25, said bearing blocks containing suitable bearings 2Bwithin which the shafts 21 and 28 are journaled.. The shafts 21 and 28may carry the grinding rolls l5 and i6.

Positioned between the bearing blocks 2@ and 25 is a set of shims 25.The edges of the shims 29 are protected from dust by means of coverplates 30.

The end of the outer bearing block 2d rests against an end plate 3|which has a compression spring 32 bearing thereagainst. The compressionspring is positioned between the end plate 3| and a presser plate 33.The presser plate is movably positioned within the guiding frame 2|, theadjustment being obtained by means of screws 34 mounted in internallythreaded apertures in the end of the guiding frame 2|. compressionspring 32 is suiciently heavy to prevent any appreciable movement of thebearing blocks 2d and 25 relative to each other, the main function ofthe compression spring being to dampen vibration.

The spacing between the rolls l5 and |B carried by the shafts 21 and 28journaled in bearing blocks 24% and 25 is regulated by the shims 29. Thedistance between the rolls can therefore be regulated with great nicetyby the or the removal of the shims. These shims may have an individualthickness of 0.001 inch. In order to facilitate the removal of shimswhenever it is necessary to adjust the rolls relative to each other, theend plate 3| is provided with a boss 36 in which the end of a rod 31 isiirmly attached. The rod 31 extends beyond the guiding frame 2|, theouter end of said rod being externally threaded as indicated at 38.Threadedly mounted on the end of this rod is a sprocket wheel 39, athrust bearing 40 being positioned between the sprocket wheel and theend wall of the guiding frame 2|. A chain 4| may connect the sprockets39 and 39' mounted on rods in opposing guiding frames by Preferably, the

introduction G This y l 35 d1 by means of ythe belt drive 48. The shaftd1 finer state of division than others. The cracked 35 the end of theguiding frame 2|. connected by means of a rubber hanger 10 which Asshown in Figs. 2, 3, 4, and 5, the rolls of may consist of strips ofrubber clamped at their every unit are driven from opposite ends. Forends to brackets 68 and 69 as by means of clampio example, the roll l5is driven from the bottom ine plates 1| and 12 respectively. Suchhangers 10 the machine whereas the low speed rolls are driven ing 61 isprovided with a shaft 13 extending in l5 gears every time the rolls arecut down for a end of the shaker arm being provided withasplit mi majoradjustment. bearing housing 16. It is evident, therefore, that On thepresent machine, however, the tension when the shaft 64 is rotated, theeccentrics 65 in the belt drive may be readily adjusted by movwilltransmit an oscillatory motion to the'shaker externally threaded rods134 and i5 carried by the peint in feeding relation t0 the grindingIOllS 3U The motor drive consists of a motor 46 mounted During thecracking of the coffee by the crackin the lower portion of the bodyframe 20. The ing rolls 6 and chaff is liberated from the 40 ablyconnected to the body frame 20. 'I'he ten- Onto the Chute 9, from WheneeSuch ner par- 40 this reason the shaft 5| may carry a. pulley 53 pieces,remain. At this point Suction iS applied as 45 which is connected byfeed belting 54 to the low by means of a boot or conduit Preferably theon a shaft which carries the low speed roll of the position 0f the boot,it is possible t0 regulate 50 the cracking unit. Similar beltingconnects the the effect of the suction upon the material fallpulley 53with pulleys 58 and 59, as for example ing off the lower end of theshaker screen Withthe belting 60 and 6 Obviously, therefore, the out thenecessity of modifying the size or speed belts 54, 56, 60 and 6| may betightened by movof the suction fan |2 connected to said conduit 55 ingthe guiding frames of the grinding rolls out- Furthermore, by adjustingthe position 0f 55 wardly. If it is desired to only tighten belts 56 theboot with respect to the end of the shaker and 6|, then the upperguiding frames of the screen 8, the amount of chaff being removed maycracking rolls may be brought closer together by be regulated andcontrolled. means of the turnbuckle 43. Positioned between the lower endof the shaker 50 A similar arrangementof beltng but on the screen 8 andthe chute 9 and extending beyond 60 opposite side of the machineconnects the high the edge of the housing 18 enclosing the grinding bedescribed hereinafter. either be mounted as an extension of the shaker 3After the coiee has been fed from the hopper housing 61 or it may bestationary. The strings 70 through the outlet 3 by the feeding roll 5and and other foreign materials retained by the string shaker assemblyor housing 61. This shaker the grinding rolls I5 and I6. 75

In adjusting the apparatus described hereinabove, it has been found thatcracking rolls 6 inches in diameter and 36 inches long give the bestresults. These cracking rolls are set up to about within 0.012 inch. Thegrinding rolls, on the other hand, are at least 8 inches in diameter andare set up to about within 0.008 inch of each other. The use of largediameter rolls for grinding increases the grip and permits themaintenance of a uniform grinding or cutting action. Furthermore, thecoiee is more uniformly spread out over the rolls. The cracking rollsmay be provided with 8 teeth per inch whereas the finishing or grindingrolls may be provided with '20 teeth per inch.

Mention` has been madeA hereinabove of the strength of the spring 32used in the bearing block guides. It has been found that instead ofemploying short and relatively weak springs, greatly improved resultsare obtained when very strong springs are used. The springs used in theguiding frames in which the grinding rolls are journaled have a 6,000pound deection per inch, in an experimental unit made in accordance withthis invention. The use of such a strong spring is important because itkeeps the rolls in place and does not permit them to vibrate, therebyinsuring uniformity in operation.

Attention should also be called to the fact that the shaker screen 8 isrelatively short. When 6 inch cracking rolls and 8 inch grinding rollswere used, the shaker screen 8 was only 24 inches long. The use of ashort screen of this sort is important in that it prevents the coffeefrom becoming aerated and losing avoring characteristics.

After the coiTee passes through the grinding or finishing rolls l5 andI6, it is discharged through the conduit 80 into the mixing 'unit l1.

As pointed out hereinabove, the mixing unit blends the ground coffeewith the separately ground chaff at a low speed so that the coffee isnot subjected to attrition or rubbing. Coffeev thus mixed is then whichsupply the can chines.

I claim:

1. A method ofmanufacturing coffee characterized by enhanced flavorextracting properties, which comprises cracking the roasted coffee,separating the flnes from the coarser coffee and chaff,v separating thechaff from the coarser coffee in the substantial absence of fines,grinding the fines and coarser coffee in the substantial absence ofchaff, separately grinding the chaff, and nally mixing the ground coffeeand separately ground chaff together to form a finished coiee.

2. In a method of preparing coffee having endischarged into hoppersfilling or packagingA mahanced flavor extraction properties, whichcomprises cracking the coffee, separating the nes from the coarsercoffee and chaff, separating the chaff from the coarser coffee in thesubstantial absence of fines, and then subjecting the iines and coarsecoffee to a single grinding operation in the absence of chaff.

3. In a method of manufacturing coffee having enhanced flavor extractionproperties, the step of grinding the coiee in the substantial absence ofchaff, separately grinding the chaff, and then mixing the ground coieeand chaff to form a finished coffee containing substantially noparticles adapted to remain on a No. 51/2 sieve and over 70% passing aNo. 4% sieve but retained on a No. 28 sieve. c

LELAND S. MAEDE.

